MOUNTAIN VIEW, Calif. — As they celebrate their 30th anniversary, the Allman Brothers Band are looking both forward and backward.

The Southern-rock band rolled like a locomotive into the Shoreline Amphitheatre on Sunday for the first of two San Francisco Bay Area dates with a new guitarist — Derek Trucks, the 20-year-old nephew of founding Allman Brothers drummer Butch Trucks — and two new songs.

The Allman Brothers also offered tributes to their past and to the late Jerry Garcia, the Grateful Dead singer/guitarist who would have turned 57 Sunday.

Widely considered the originator of the Southern-rock genre, the band was born at a Jacksonville, Fla., jam session in 1969. Its trademark dual-lead-guitar sound paved the way for bands such as Lynyrd Skynyrd, the Marshall Tucker Band and the Outlaws.

With Harley-Davidson motorcycles three rows deep outside the amphitheater, the band — which was inducted into the Rock and Roll Hall of Fame in 1994 — took the stage casually, warming up with the instrumental "True Gravity," from the 1990 album Seven Turns.

Betts' signature volume-swells rode a wide, bouncy groove on "Ain't Wastin' Time No More" (RealAudio excerpt), from Eat a Peach (1972). The harmonic guitar interplay between Betts and Trucks emerged from under the thunderous barrage of Oteil Burbridge's bass.

On the bluesy "You Don't Love Me," Trucks demonstrated his lead power with near-metallic slide-guitar tones.

"We're gonna be with you for a while tonight. We got nothin' but time, so let's dig in," said Betts, who wore a white cowboy hat and red and white tie-dyed T-shirt with ripped-off sleeves that revealed tattoos covering both arms.

Known for their extended blues- and jazz-based jams and psychedelic light show, the Allman Brothers' current lineup includes four original members — organist/singer Gregg Allman, Betts, drummers Trucks and Jaimoe (born John Lee Johnson) — as well as Derek Trucks, Burbridge and percussionist Marc Quinones.

Some fans might have missed guitarist Warren Haynes and bassist Allen Woody, who

played with the band from 1989 until 1997, when they left to focus on their

power trio, Gov't Mule.

But the present lineup delivered what Alex Vaughn, a 28-year-old fan from St. John, Virgin Islands, called "psychedelic classic-rock guitar."

"There's not really a lot of it out there," said Vaughn, who said he was given a free ticket by a stranger in the parking lot. "You've gotta thrive on it. [They're] living legends."

Betts launched the band into a new song, the ballad "Good Times," which reflected on a San Francisco rock landmark: "The old Fillmore was a great place to play/ They tore it down 'cause it got in the way/ Funny how things come and go that way/ After all these years, we're still standing here/ Good times don't fade away."

Photos of Harleys and footage from the biker film "Easy Rider" played on the screen behind the band during the dark "Midnight Rider" (RealAudio excerpt). Continuing the nod to biker culture, hundreds of images of tattoos flashed on the screen during the scorching rocker "Good Clean Fun," from Seven Turns (1990).

The band jammed on the Grateful Dead's "Franklin's Tower," using it to launch into their classic, soaring love song "Blue Sky," from Eat a Peach. The formidable three-drummer team underscored the song with an airy, polyrhythmic beat.

Allman sang the heavy "End of the Line," from Shades of Two Worlds (1991), another in a canon of songs with road-weary, soul-searching lyrics: "And now the gravity of trouble was more than I could bear/ At times my luck was so bad, I had to fold my hands/ Almost lost my soul, rarely I could find my head/ Wake up early in the morning, feeling nearly dead."

Allman's downbeat lyrics are anything but gratuitous — among other setbacks, the band endured a tragic double blow when founding guitarist Duane Allman (Gregg's older brother) and bassist Berry Oakley died in similar motorcycle accidents in 1971 and 1972, respectively.

The second set started with two acoustic numbers, "Seven Turns" and "Melissa." Then Betts introduced another new tune, the complex instrumental "J.J.'s Alley," as "kind of a bebop ... like we were doing in the '40s."

Blues singer/guitarist Susan Tedeschi, who had played an opening set, joined the band for the blues standard "Stormy Monday," trading verses with Allman.

Betts then introduced Bay Area saxophonist Martin Fierro for the driving instrumental "In Memory of Elizabeth Reed" (RealAudio excerpt). "Martin played with Jerry Garcia," Betts said. "Speaking of Jerry, it's his birthday tonight. We remember good old Jerry. He's always been with us here on this stage."

The Allmans and the Grateful Dead played together frequently, most notably at the Watkins Glen festival with the Band in 1972. The Dead played regularly at the Shoreline Amphitheatre, and a road outside the venue is named for Garcia.

Images of Garcia flashed on the screen during "Elizabeth Reed" and later, during "Revival," with '60s icons such as singer Janis Joplin, civil-rights activist Martin Luther King Jr., concert promoter Bill Graham and President Richard Nixon.

The past nearly came to life during an eerie rendition of "No One to Run With." Film footage of Duane Allman was superimposed against live shots of the band, creating the illusion that the late guitarist was onstage between Betts and guitarist Trucks.